Pruritus is a condition involving localized or general itching that is a common and distressing symptom in a variety of diseases. Although usually occurring in the skin, pruritus can also occur in non-cutaneous sites such as mucous membranes. Pruritis is a frequent manifestation of localized skin disorders caused by hypersensitivity reactions such as allergic reactions to insect bites or to environmental allergens, urticaria, dermatoses of fungal and bacterial origins, ectoparasite infections, and hemorrhoids. Pruritis may also be a symptom caused by systemic diseases, including, for example, hypothyroidism, thyrotoxicosis, mucocandiasis in diabetes mellitus, and Hodgkin's disease. (see, for example, Herndon, J. H. Jr., Int. J. Derm. 14, 465–484 (1975); Winkelmann, R. K., Med. Clins. N. Am. 66, 1119–1133 (1982). Many systemic diseases and skin disorders are accompanied by bouts of persistent or recurrent pruritis. The clinical importance of pruritus is irrefutable but effective treatment has been limited by current available treatments.
Current treatments for pruritus include the use of antihistamines and corticosteroids. Both, however, have undesired side effects. Antihistamines may relieve pruritis but can cause drowsiness or dry mouth. Some topical preparations contain chemicals such as corticosteroids but are limited to treating those with a steroid responsive disorder. These messy topical preparations provide relatively short-duration antipruritic activity and must be applied frequently to continue relief from pruritis.
Thus, there is a continuing need for development of new and improved compositions that are inexpensive and effective in treating and preventing inflammation and/or pruritus resulting from a wide variety of causes.
The poison ivy plant and its relatives are ubiquitous throughout the United States. Allergic reactions from these plants will affect millions of Americans every year. Researchers have found that 85% of the population will develop an allergic reaction if exposed to poison ivy. Although allergic contact dermatitis can occur in any setting, many cases are related to exposures in the workplace. Outdoor workers, including surveyors, firefighters, park and highway maintenance workers, utility-line workers, and farm workers are most at risk. When all occupationally related illness in the United States was last estimated, allergic contact dermatitis accounted for 7%, at an annual cost of $250 million in lost productivity, medical care, and disability payments.
Contact with the oil from a poison ivy plant often results in an allergic skin reaction that is manifested by pruritis and bothersome rashes that progress to painful blisters. The oil, urushiol, is found in all parts of the poison ivy plant, including the leaves, stems, roots, and berries. Urushiol is invisible and sticky and may be carried on garden tools or even on pet's fur, where, unless the oil is detected and removed, it maintains its potency on the surface of such objects for years. The rash is spread by touching an area or object contaminated with urushiol and then touching a “clean” area, for example, wiping the forehead with a contaminated hand. In this way, the unaware urushiol-carrier may unknowingly contaminate other areas not initially in direct contact with poison ivy, such as the mouth, genital, or eye areas. Urushiol can penetrate the skin within minutes and the symptoms of pruritis and rashes will not appear for days.
Sensitivity to urushiol can develop at any time and seems to develop over several exposures. Repeated bouts of the allergic contact dermatitis from poison ivy can become more severe. Without treatment, the symptoms of the rash will normally disappear in 14 to 20 days.
For those who are highly sensitive to poison ivy, they may be unable to wait for the symptoms to dissipate. In some cases, contact with poison ivy results in a severe reaction, including swelling of the face and throat. This reaction can impair breathing and warrants immediate treatment at a hospital. For those with less severe reactions not warranting emergency medical treatment, many still cannot handle the itch without some relief.
Thus, the above treatments have not been satisfactory. To prevent poison ivy, the current approach is to learn to recognize the poison ivy plant and simply avoid it. However, as noted previously, certain occupations may be unable to prevent contact with the plants. There is therefore a need in the art for an improved composition and method of treating and preventing pruritis which solves the problems of the aforementioned compositions and methods.
Accordingly, it is a primary objective of the present invention to provide an improved therapeutic method to treat pruritic conditions of the skin or mucous membrane, particularly caused by exposure to poison ivy.
It is a further objective of the present invention to provide an effective therapeutic composition that prevents and treats inflammatory and/or pruritic conditions caused by poison ivy or other diseases and disorders.
It is a still a further objective of the present invention to provide a method for manufacturing compositions to prevent and treat inflammation and/or pruritis.
The method and means of accomplishing each of the above objectives as well as others will become apparent from the detailed description of the invention which follows hereafter.